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Mirrors > Home > ILE Home > Th. List > ax-precex | GIF version |
Description: Existence of reciprocal of positive real number. Axiom for real and complex numbers, justified by Theorem axprecex 7817. (Contributed by Jim Kingdon, 6-Feb-2020.) |
Ref | Expression |
---|---|
ax-precex | ⊢ ((𝐴 ∈ ℝ ∧ 0 <ℝ 𝐴) → ∃𝑥 ∈ ℝ (0 <ℝ 𝑥 ∧ (𝐴 · 𝑥) = 1)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | cA | . . . 4 class 𝐴 | |
2 | cr 7748 | . . . 4 class ℝ | |
3 | 1, 2 | wcel 2136 | . . 3 wff 𝐴 ∈ ℝ |
4 | cc0 7749 | . . . 4 class 0 | |
5 | cltrr 7753 | . . . 4 class <ℝ | |
6 | 4, 1, 5 | wbr 3981 | . . 3 wff 0 <ℝ 𝐴 |
7 | 3, 6 | wa 103 | . 2 wff (𝐴 ∈ ℝ ∧ 0 <ℝ 𝐴) |
8 | vx | . . . . . 6 setvar 𝑥 | |
9 | 8 | cv 1342 | . . . . 5 class 𝑥 |
10 | 4, 9, 5 | wbr 3981 | . . . 4 wff 0 <ℝ 𝑥 |
11 | cmul 7754 | . . . . . 6 class · | |
12 | 1, 9, 11 | co 5841 | . . . . 5 class (𝐴 · 𝑥) |
13 | c1 7750 | . . . . 5 class 1 | |
14 | 12, 13 | wceq 1343 | . . . 4 wff (𝐴 · 𝑥) = 1 |
15 | 10, 14 | wa 103 | . . 3 wff (0 <ℝ 𝑥 ∧ (𝐴 · 𝑥) = 1) |
16 | 15, 8, 2 | wrex 2444 | . 2 wff ∃𝑥 ∈ ℝ (0 <ℝ 𝑥 ∧ (𝐴 · 𝑥) = 1) |
17 | 7, 16 | wi 4 | 1 wff ((𝐴 ∈ ℝ ∧ 0 <ℝ 𝐴) → ∃𝑥 ∈ ℝ (0 <ℝ 𝑥 ∧ (𝐴 · 𝑥) = 1)) |
Colors of variables: wff set class |
This axiom is referenced by: recexre 8472 recexgt0 8474 |
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